Why it’s important to reintroduce

So, you’ve trialled a good period of eliminating high-FODMAP foods. You think it’s helping. Now what?

The next stage should be reintroduction. However, I feel many of us are getting stuck in stage 1, because we feel less bloated and have gained some control of our symptoms. It almost doesn’t make sense to rock the b(l)oat at this point.

But why is it so important to reintroduce? Why don’t we all just stay in the elimination phase, knowing our symptoms are more controlled?

Integral to the reason that they cause symptoms is because they’re brilliant for your gut. There is a huge crossover in foods being high-FODMAP and being prebiotics. Whilst you may have heard of probiotics, prebiotics are equally important for your gut health. They provide a favourable gut environment for the growth of probiotics. It’s like the fertiliser you put on your lawn to help the grass and flowers grow. They are non-digestible, hence why they can give symptoms; they are fermented by the good bacteria, which produces gas as a by-product. Onion and garlic are prebiotics; they are essential for a healthy gut. This is why it is so important to reintroduce.

Low-FODMAP should not be for-life

It is never a good idea to cut anything out. The low-FODMAP diet is not designed to be for-life, precisely because cutting out food groups can be detrimental to your health. There is increasing research into gut health and the gut microbiome (i.e. the microbial environment in your gut) and evidence so far strongly suggests that gut health can influence everything from immunity to depression.

Although I am very excited by the growing appreciation for the low-FODMAP diet, I am slightly concerned. If we rely too heavily on low-FODMAP foods, especially as they become more readily available in supermarkets, it becomes all too easy to sit comfortable in the elimination phase.

Remember that everything you consume affects your gut microbiome. Cutting out food groups will alter the population of gut bacteria. In his book, The Clever Guts Diet, Dr Michael Mosley describes how the “addictiveness” of chocolate could in part be due to your gut microbiome: in simplified terms, the more of it you eat, the more you promote the growth of bacteria which respond to it. These bacteria send signals to encourage you to eat more of it, because that’s what they want. So, you eat more chocolate and continue encouraging the growth of these bacteria! It’s an incredibly clever system. And it is dynamic. Stool samples from different diets clearly show how different gut bacteria populations are in people who eat different food groups. This is partly why having a balanced diet with everything in moderation is so vital to health. And this is partly why you really are what you eat.

How should you reintroduce then?

It is not always straightforward. Think of it like the science experiments you did at school when you had to outline your dependent and independent variables. It is only a “fair” experiment if you have one dependent (changing) variable. This means you need to reintroduce one food group at a time in order to make it a fair test.

Since IBS is not solely dependent on food, but also on mood, sleep, stress, exercise etc., it is not always easy to control for every variable. Do your best to create a controlled environment. Formally, you should reintroduce with the guidance of a dietician. This is obviously the ideal, but perhaps not always practical. This works on the principle of reintroducing one of the O/D/M/Ps of the FODMAP groups at a time. It is on my to-do list to contact a dietician to do this formally, but in the mean time I don’t want to deprive my gut of incredible prebiotic foods and perhaps cause myself harm in the long run! My advice to keep your gut bacteria balanced, is to add small amounts of high-FODMAP foods if you feel comfortable. Try adding red onion to a pasta sauce two or three times a week. You may find that your symptoms remain stable. Add in garlic to otherwise low-FODMAP meals. Don’t be afraid to reintroduce!

The FODMAP app from King’s College London has dedicated guidance on each phase of the low-FODMAP diet.

For more information on the Clever Guts Diet, visit the website or buy the book.

Follow me on Instagram @the_fodmap_medic to learn how I’ve been reintroducing high-FODMAP ingredients and on Twitter @thefodmap_medic.